The present invention relates to a system for holding and dispensing liquids. In particular, the present invention relates to a container for holding and dispensing liquids having a collapsible liner intrinsically formed with the wall of the container.
Numerous manufacturing processes require the use of ultrapure liquids such as acids, solvents, bases, photoresists, dopants, inorganic, organic and biological solutions, pharmaceuticals, and radioactive chemicals. Such industries require that the number and size of particles in the ultrapure liquids be controlled to ensure purity. In particular, because ultrapure liquids are used in many aspects of the microelectronic manufacturing process, semiconductor manufacturers have established strict particle concentration specifications for process chemicals and chemical-handling equipment. Such specifications are needed because, should the liquids used during the manufacturing process contain high levels of particles, the particles may be deposited on solid surfaces. This can in turn lead to product failure and reduced reliability.
Accordingly, storage, transportation, and dispensing of such ultrapure liquids requires containers capable of providing adequate protection for the retained liquids. Two types of containers used in the industries are rigid-wall containers and collapsible-liner containers. Rigid-wall containers are conventionally used because of their physical strengths, thick walls, and ease of manufacture. Such containers, however, introduce air-liquid interfaces when dispensing the retained liquids by pump. This leads to unwanted particle generation in the liquids.
Alternatively, collapsible-liner containers are capable of reducing such air-liquid interfaces by collapsing the liners while dispensing. Additionally, such containers have greater recyclability, as the retained liquids only contact the collapsible liner. However, inserting liners within the containers require extra manufacturing steps after molding or casting. Moreover, because of the flexible nature of the liners, they are unable to provide adequate protection against environmental conditions. Interstitial air may become entrained between the outer wall of the container and the collapsible liner. Such interstitial air may permeate through the collapsible liner over time, contaminating the retained liquids.
Containers with collapsible liners also affect the vibrations in the retained liquids during transportation, increasing particle generation in the liquids through unwanted jostling. Such containers also may have pinholes intrinsic in the thin liners at low levels because of the manufacturing methods used, or caused by vibrations during transportation. As such, there currently exists a need in the industry for containers that combine the benefits of a rigid-wall container with the those of a collapsible-liner container.